wyoming blood lecture blog post
TRANSCRIPT
WAYS TO CHALLENGE A BLOOD TEST IN WYOMINGE R I N G E R S T E N Z A N G - E H G L AW F I R M - F E B R U A R Y 6 , 2 0 1 5
15
CHALLENGE!
C H A L L E N G E T H E S W A B U S E D D U R I N G T H E P R O C E D U R E
• “Alcohol solutions should not be used as a skin antiseptic.” Rules and
Regulations for Chemical Analysis for Alcohol Testing Chapter 3, section 3(b)
• Ethanol-based hand sanitizers (EBHSs) are used in most health care facilities in the United States
C H A L L E N G E T H E A N T I S E P T I C P R O T O C O L B E F O R E T H E D R A W
• Swabbed in a circular motion away from the site of the draw (don’t just move the dirt around!)
FA N C Y S C I E N C E W O R D
Candida Albicans = yeast that lives on human skin and creates alcohol as a waste product
CHALLENGE!
C H A L L E N G E T H E N E E D L E U S E D T O D R A W B L O O D
• Phlebotomists switch out the blood kit needle for an elongated tube butterfly needle or a swap out for a smaller gauge needle (easier/causes less pain)
• “Collected using standard medical procedures and equipment for obtaining blood samples.” Rules and
Regulations for Chemical Analysis for Alcohol Testing Chapter 3, section 3(a)
CHALLENGE!
R E D B L O O D C E L L S A R E B R E A K A B L E
• A needle that is too small can cause the blood cells to rupture
• Rigorous shaking from mixing preservatives or shipping by mail
FA N C Y S C I E N C E W O R D
Hemolysis = the breaking of blood cells, most of which are red blood cells.
C H A L L E N G E T H E T U B E S U S E D T O C O L L E C T T H E S A M P L E
• 2 gray tubes
• The tube must “contain an appropriate anticoagulant and a preservative, such as potassium oxalate or EDTA (ethylenediaminetetraacetic acid) and a minimum of 0.1% sodium fluoride.” Rules and Regulations for Chemical Analysis
for Alcohol Testing Chapter 3, section 3(c).
CHALLENGE!
W H Y P R E S E R VAT I V E S ? R E M E M B E R O U R F R I E N D C A N D I D A A L B I C A N S
J. Chang & S.E. Kollman, The Effect of Temperature on the Formation of Ethanol by Candida Albicans in Blood, Journal of Forensic Sciences, Vol. 34, 105-109 (1989)
• The ability of yeast to convert sugar into ethanol has been harnessed by the biotechnology industry to produce ethanol fuel
• A diabetic will have large amounts of glucose present in their blood making it very hospitable to yeast — leading to larger amounts of fermented ethanol
S O W H AT I F T U B E I S E X P I R E D ?
• Yeast is everywhere
• You can contaminate a blood sample by simply touching the area where the needle enters the blood tube, prior to inserting the needle into the tube
T U B E I N V E R S I O N
According to BD, “inversion should be slow enough to allow the air bubble in the tube to completely traverse the length of the tube.”
• The tube must be inverted in accordance with the manufacturer’s recommendations(5-8 times) following the collection of blood, so that the powder is homogeneously dispersed throughout the collection tube
OKAY, LET’S DIG IN!G A S C H R O M AT O G R A P H Y
C O L U M N F - I - D
C O L U M N
T E S T S A M P L E
F - I - D
45% FORMED ELEMENTS 55% PLASMA
PLATELETS (4.8%)
RED BLOOD CELLS (95.1%)
WHITE BLOOD CELLS
(0.1%)
NEUTROPHILS (54-62%)
EOSINOPHILS (1-3%)
BASOPHILS (< 1%)
MONOCYTES (3-9%)
LYMPHOCYTES (25-33%)
ELECTRO- LYTES
WATER (92%)
PROTEINS (7%)
WASTES (95.1%)
NUTRIENTS VITAMINS
HORMONES
GASES
N2 O2 CO2ALBUMINS GLOBULINS FIBRINOGEN
LOTS OF DIFFERENT MOLECULES DISSOLVE INTO THE PLASMA
N-PROPANOL
ETHANOL
METHANOL
ACETONE
ACETALDEHYDE
ISOPROPANOL
THE TRACK SURFACE IS “STICKY” WHICH SLOWS DOWN THE MOLECULES
Photo credit: Anthony Scott Photography
Chromatography — The separation of a mixture of "stuff" through a medium (liquid or gas) through which the molecules travel at different speeds.
R E A L LY FA N C Y S C I E N C E W O R D
CHROMATOGRAPHY
Good$chromatogram$• Tall,$skinny$peaks$• Resolu8on$of$ethanol$and$$$$$$$$internal$standard$
CLEAN RACE RESULTS
Thanks to Dr. Jimmie Valentine for these chromatograms
Ethanol(not(separated(from(acetone(–(a(diabe4c(has(acetone(in(their(blood(
Slide&courtesy&of&Dr.&Jimmie&L.&Valen7ne&
C H A L L E N G E C O -E L U T I O N O F S A M P L E S O N C H R O M AT O G R A M
FA N C Y S C I E N C E W O R D
Co-elution = Samples leaving the column and entering the flame ionization detector at the same time.
• Two samples leaving at the same time makes it impossible to tell how much of each sample was in the blood.
CHALLENGE!
Thanks to Dr. Jimmie Valentine
Peak%tailing%Poor%chromatography%showing%peak%tailing%producing%addi6onal%area%to%be%included%in%quan6ta6on%
C H A L L E N G E P E A K S T H AT A R E N O N -S TA N D A R D
Co-elution = Samples leaving the column and entering the flame ionization detector at the same time.
• Peaks that are asymmetrical, either “tailing” (as on left) or “fronting” peaks.
• Peaks that “wiggle” or that are too fat
• Peaks that go below the baseline
• “Sudden issues with tailing indicates column contamination, possibly caused by a recent dirty sample”
CHALLENGE!
Thanks to Dr. Jimmie Valentine